Isolation, chemical and biological characterization of margaratensin, a neurotensin-related peptide from the skin of Rana margaratae.
A new neurotensin (NT)-related peptide, margaratensin, was obtained by Sep-Pak C18 and RP-HPLC from methanol extracts of the skin of Chinese frog Rana margaratae. The structure of the peptide has been determined to be Asp-Lys-Arg-Pro-Tyr-Ile-Leu-His-Glu, which is found to be homologous to the COOH-terminal sequence of NT, but has an extra His-Glu at the COOH-terminus. The synthetic preparation was shown to be indistinguishable from the native peptide during HPLC, amino acid analysis and bioassay. Margaratensin exhibited a hypotensive effect in the rat but the response was weaker than NT. The peptide could induce a potent and reproducible contractile activity on GPI which was different from xenopsin, another NT-related peptide from amphibian skin.
Tang
Y Q
YQ
Shanghai Institute of Materia Medica, Academia Sinica, PRC.
Tian
S H
SH
Hua
J C
JC
Wu
S X
SX
Zou
G
G
Tsou
K
K
Wu
G F
GF
Zhao
E M
EM
D000595:Amino Acid Sequence; D000818:Animals; D000959:Antihypertensive Agents; D001794:Blood Pressure / Q000187:drug effects; D006168:Guinea Pigs; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D011898:Ranidae; D051381:Rats; D012867:Skin / Q000737:chemistry*; D013329:Structure-Activity Relationship
D000959:Antihypertensive Agents; D010455:Peptides; C067265:magaratensin